Selenium speciation in root soil samples collected from the Poyang Lake basin of Jiangxi Province was investigated in this paper.The results show a significant positive correlation between the species and total amounts of selenium in root soil.The residue species of selenium occupies 12.32% of total selenium,and the species of bound-state humic acid approximately accounts for 66.23% of the total amount of selenium in root soil.It is held that the process of selenium adsorption in soil organic substance and clay mineral causes selenium enrichment in root soil.